In a conventional semiconductor device, in order to dissipate heat generated in mounted semiconductor elements by making contact with a cooling element that is operated as a heat radiator, a pattern having a shape for enhancing adhesiveness to the cooling element is formed by applying a heat dissipating material (for example, refer to Japanese Unexamined Patent Publication No. 2009-277976). In addition, the device is shipped with the coated surface being exposed.
In the semiconductor device described above, there is a risk that the semiconductor device reaches a high temperature under a situation in which the environmental temperature is not sufficiently controlled at the time of shipment to a customer or during transportation to a customer, etc. In such a case, there has been a problem in that, if the coated heat dissipating material is a phase transition material, the heat dissipating material is liquefied, and if a shock is applied to the pattern of the heat dissipating material, the shape of the pattern is collapsed.